What Are Oil Sands?

About Oil Sands

The oil sands is a natural geologic formation that contains a mixture of water, clay, sand and heavy, viscous oil called bitumen. These deposits are found in about 70 countries in the world, with the largest reserves located in Canada.[1]

Canada has total proven oil sands reserves of over 170 billion barrels, according to the U.S. Energy Information Administration[2]. The majority of these reserves are located across 54,000 square miles in three Alberta deposits: the Athabasca, Peace River and Cold Lake. Once produced, the thick bitumen is either diluted or upgraded before being transported through a vast pipeline infrastructure, a majority of which goes to refineries located in the U.S. Midwest for processing. The oil produced from oil sands can be refined and used to make asphalt, gasoline, jet fuel and some chemicals.

Source: Canadian Association of Petroleum Producers

Proximity and a trusted trade relationship have positioned Canada as the largest supplier of oil to the United States, which consumes 99 percent of Canadian petroleum exports[3]. About half of that supply is derived from the oil sands. Produced since the late 1960s, Canadian oil sands production has grown to account for more than 1 million barrels/day of U.S. oil imports[4].

Source: Canadian Association of Petroleum Producers

Extraction

Bitumen is oil too heavy or thick to flow without being diluted or heated. Oil sands producers typically deploy one of two extraction methods, surface mining or in situ drilling, depending on the depth of the reserves.

Surface Mining

Surface mining is used when bitumen is close to the surface (within 250 feet). About 20 percent of oil sands reserves are close enough to the ground’s surface be mined[5].

Mining shovels dig into the formation and transport the sand mixture to large trucks. The trucks then carry the sands to crushers that break down the clumps and remove rocks.

Next, the mixtures is steamed and sent to the plant using a process called hydro-transport. During transportation, the bitumen begins to separate from the sand and clay.

The final step occurs in separation vessels where the bitumen forms a frothy substance at the top and the clay, sand and other minerals – or tailings – sink to the bottom. The bitumen is removed and the fine tailings are stored in ponds at oil sands mining operations and left to settle so that the land reclamation process can begin.[6]

What are tailings ponds?

Watch a quick overview of how one company is approaching tailings management.

In Situ Drilling

In situ (Latin for “in place”) drilling processes are deployed when reserves are deeper than 250 feet. Eighty percent of oil sands reserves are recoverable through in situ technology.

During in situ extraction, a number of wells averaging depths of 1,300 feet are drilled into the ground. Advances in drilling technology such as directional drilling allow in situ operations to drill as many as 20 wells at a time with limited land disturbance.[7]

In a majority of in situ operations, steam is injected into the well to liquefy the bitumen that is then pumped to the surface through another well. This process is known as steam-assisted gravity drainage (SAGD). Current investments in advanced technology will make the method of extraction more widely used in the years to come.